JPH0619215Y2 - Ladder type electric filter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is used for a radio device or the like, and accommodates a series resonator and a parallel resonator forming a required circuit in a case, and The present invention relates to a ladder-type electric filter which is formed by projecting connection legs of a terminal plate which is an external connection terminal of the circuit and is mounted on a printed circuit board to form a filtering circuit from both of the opposite side surfaces of the case.

[Prior Art] Wireless devices and the like are desired to be smaller and thinner.
Therefore, since the filtering circuit is configured by a series of basic unit circuits including a series resonator and a parallel resonator, only one to a few units of the basic unit circuit are housed in a case and an electric filter is installed. It has been proposed to make the filter itself as thin as possible by configuring the above.

This kind of electric filter is mounted on the top of the printed circuit board,
The connection leg of the terminal plate protruding from the side surface of the case is bent and connected to the required conductive path of the printed circuit board to form the required filtering circuit.

By the way, in this electric filter, the fixing means to the printed circuit board is such that the connecting leg of the terminal plate which becomes the external connecting terminal is projected from only one side surface of the case, and the connecting leg is soldered to the printed circuit board or is inserted into the through hole. It was by inserting. For this reason, since it is supported by a cantilever, fixing of the filter to the printed circuit board becomes insufficient, rattling occurs due to impact, the characteristics become unstable, and in some cases it falls off from the printed circuit board. There was a drawback.

Therefore, in order to eliminate this drawback, connecting legs of a plurality of terminal plates electrically connected to the series resonator or the parallel resonator,
What was made to project from either side of the case was proposed in Japanese Patent Application No. 63-110142.

In this structure, both ends can be supported by inserting the connecting legs protruding from both sides of the case into the through holes of the printed circuit board or fixing them by means such as soldering, and the filter is stable. Has the advantage of being retained in.

[Problems to be Solved by the Invention] As described above, in the Japanese Patent Application No. 1-16047, the input side terminal plate and the output side terminal provided with the connecting legs are configured so that the connecting legs are projected from both side surfaces of the case. Board or one of the ground side terminal boards is integrally assembled to a synthetic resin case by insert molding, and the connection leg is projected from one side of the case, and a terminal board equipped with another connection leg is attached. It has been proposed that the connection leg is inserted from an opening formed on the other side surface of the case and the connecting leg is projected from the other side surface of the case.

In this product, since one terminal plate is integrally assembled to the synthetic resin case, unlike the structure in which openings are formed on both sides of the case and each opening is shielded by a sealing plate, it is on one side surface side. As a result, it is easy to insert the connection leg into the insertion hole formed in the sealing plate, the assembly process is facilitated, and the sealing process is performed only on one side of the case, which is advantageous in that the airtightness is good.

It is an object of the present invention to improve the connection strength of a terminal plate assembled to a synthetic resin case and further improve the airtightness inside the case in such a configuration.

[Means for Solving the Problems] In the present invention, the terminal plate assembled to the synthetic resin case is formed with a rough surface on the connecting leg base surface embedded in the case, and is embedded in the case. A connecting hole through which resin penetrates is formed on both shoulders of the connecting leg base, and a blocking ridge is formed just inside the connecting leg base to prevent resin from flowing inward from the connecting leg base. It is what

[Operation] By forming a rough surface on the connection leg base surface, the rough surface improves the adhesion to the synthetic resin material, prevents the terminal plate from being separated from the synthetic resin case, and improves the hermeticity. To do.

Further, by forming the connection holes through which the resin penetrates in the shoulder portions on both sides of the connection leg base embedded in the case, the resin is filled in the connection holes in a penetrating manner, so that the connection strength with the synthetic resin case is high. Is improved.

Furthermore, by forming a blocking ridge just inside the connecting leg base, the blocking ridge prevents resin from flowing inward from the connecting leg base, and the case wall surface at the connecting leg base position is kept in a predetermined shape. As a result, the strength of the wall surface is improved, the airtightness of the position is improved, and when the resin flows into the case, it hinders the mounting of other various members to be inserted through the case opening, but such a problem disappears. .

Thus, the adhesion with the synthetic resin material and the connection strength are improved, the strength of the case wall surface is improved, and the ladder type electric filter in which the circuit member is incorporated in the synthetic resin case is made airtight. A rich and high strength composition can be obtained.

Both ends can be supported by inserting the connecting legs protruding from both sides of the case into the through holes of the printed circuit board or fixing them by means such as soldering, and the filter can be stably held. Becomes

[Embodiment] An embodiment in which the present invention is applied to a filter F in which four resonators are housed in a case and two basic unit circuits are housed,
It will be described with reference to FIGS.

Reference numeral 1 is a thin rectangular synthetic resin case made of an insulating material, and its forming means will be described.

In this case 1, a ground terminal plate 9 having a connecting leg 9t protruding from one end is integrally assembled. As this assembling means, as shown in FIGS. 2 and 3, means for integrating the synthetic resin case 1 and the ground terminal plate 9 by insert molding in the molding step is adopted.

In this case, the opening surface 2 is provided on one side in the synthetic resin case 1.
It is necessary to devise the internal shape so as to enable the die-cutting from the storage space 3 so that the storage space 3 in which the space is formed can be formed. Therefore, the shoulder portions 9a, 9 of the ground terminal plate 9 are
a is embedded in the synthetic resin case 1, and the shoulder portions 9a, 9
No gap is formed between a and the storage space 3.

The ground terminal plate 9 is previously processed as shown in FIGS.

That is, a rough surface 9c (FIGS. 4 and 5) formed by forming a myriad of groove grooves in the width direction by roughening on the front and back surfaces of the connection leg base portion 9b embedded in the case 1 of the ground terminal plate 9. Figure A
Form).

Further, connecting holes 9d and 9d (see FIGS. 4 and 5B) through which resin penetrates are formed in both side shoulder portions 9a and 9a of the ground terminal plate 9 which are embedded in the case 1.

Further, a blocking ridge 9e (see FIGS. 4 and 5A) is formed on the ground terminal plate 9 just inside the connecting leg base 9b to prevent the resin from flowing inward from the connecting leg base 9b. There is. The blocking ridge 9e is formed by cutting the ground terminal plate 9 into a U-shape and bending the cutting edge upward.

In addition to this structure, the blocking ridge 9e can be formed by subjecting the portion to bulging or the like.

Then, the shoulder portion 9 of the ground terminal plate 9 is formed by insert molding.
The a and 9a and the connecting leg base 9b are embedded in the synthetic resin case 1, and the ground terminal plate 9 is integrally assembled to the synthetic resin case 1. Then, the connection leg 9t formed on the ground terminal plate 9 projects from one side surface of the synthetic resin case 1.

The rough surface 9c improves the adhesion to the synthetic resin material and prevents the terminal plate 9 from coming off the synthetic resin case 1. Further, since the resin is penetratingly filled in the connection holes 9d, 9d, the connection strength with the synthetic resin case 1 is improved. Furthermore, the connection ridge base 9b is formed by the blocking ridge 9e.
The resin is prevented from flowing inward from the connection leg base portion 9b.
The case wall surface at the position is held in a predetermined shape to improve its wall strength, the connection strength with the terminal board 9 is maintained at a predetermined value, and when the resin flows into the inside of the case 1, it is inserted from the case opening 2 There will be no hindrance to the mounting of various members.

That is, the combination of the above-mentioned configurations improves the connection strength of the terminal board 9, improves the airtightness of the inside of the case 1, and produces various effects.

In the storage space 3 of the synthetic resin case 1, various members constituting a required circuit are inserted above and below the ground terminal plate 9 from the opening surface 2. The structure of this storage member will be described with reference to FIG.

First, above the ground terminal plate 9, a buffer plate 11, an input terminal plate 6 having a connecting leg 6t formed on one side edge, a thick series resonator 4a, a relay terminal plate 10a, an auxiliary terminal plate 12, and a thin parallel plate. The resonators 5a are sequentially inserted.

Below the ground terminal plate 9, the relay terminal plate 13a, the insulating plate 14, the relay terminal plate 10b, the series resonator 4b, the output terminal plate 8 having the connecting leg 8t formed on one side edge, and the auxiliary terminal plate 1 are provided.
5, parallel resonator 5b, relay terminal plate 13b, and buffer plate 16
Are sequentially inserted.

The relay terminal boards 10a and 10b are integrated by a continuous portion 10c on the front side thereof. Similarly, the relay terminal plates 13a and 13b are also integrated by the continuous portion 13c on the other side portion on the front side thereof. And the continuous part 1
In order to prevent 0c and 13c from coming into contact with other members, in the storage space 3 of the synthetic resin case 1, cutout portions 3 where the continuous portions 10c and 13c are located on both sides of the inlet portion.
a and 3b are formed.

In this mounted state, the synthetic resin case 1
The connecting leg 6t of the input terminal board 6 and the connecting leg 8t of the output terminal board 8 project from the other side surface. The connecting leg 6t of the input terminal board 6 is bent twice, and its protruding height is the same as that of the connecting leg 8t.

In this stored state, as shown in FIG. 8, the sealing plate 17 is fitted into the opening surface 2 and the connecting legs 6 are inserted into the insertion holes 18a and 18b.
t and 8t are inserted.

Thus, the electric filter F is completed by depositing the sealing plate 17 and then injecting the sealing agent 19 such as epoxy resin onto the sealing plate 17.

In the electric filter F, as shown in FIGS. 7 and 8, the connecting leg 9t projects from one side surface of the synthetic resin case 1, and the connecting legs 6t and 8t project from the other side surface. And each connecting leg 6
As shown in FIGS. 5 and 6, t, 8t, and 9t are bent twice by applying a holding die, and then bent outward, after being L-shaped bent downward.

The lower ends of the connecting legs 6t, 8t, 9t may be bent inward, and in this case, a rectangular groove may be formed on the lower surface of the case so that the bent ends can be fitted substantially flush with each other. Or
The lower ends of the connecting legs 6t, 8t, 9t may be bent in a U shape.

As shown in FIG. 8, the electric filter F is placed horizontally on the printed circuit board p, and the bent ends of the connecting legs 6t, 8t and the connecting leg 9t are soldered to the required conductive paths on the printed circuit board p. m and connect, and it is stably held by supporting both sides.
At this time, instead of soldering m, it may be inserted into a through hole to be supported.

The electric filter F serves as a basic unit circuit of the filter circuit, and by connecting the electric filter F, the filter circuit shown in FIG. 9 is constructed.

That is, the series resonators 4a and 4b are connected in series via the connection legs 6t and 8t to the input / output terminals 20 and 21, and the parallel resonators 5a and 5b are connected to the ground terminal 24 via the connection legs 9t, respectively. Connect in parallel. Thus, a filter circuit is constructed by using a plurality of electric filters F.

In the above embodiment, the ground terminal plate 9 is integrally assembled to the synthetic resin case 1 and the connecting leg 9t is projected rightward in the figure of the synthetic resin case 1. The terminal plate 8 may be integrally assembled with the synthetic resin case 1.

Further, in each of the above-mentioned embodiments, the one applied to the filter storing the two basic circuits each consisting of the two series resonators or the parallel resonators has been described, but one or three resonators are housed. Etc., the present invention can be applied to filters containing various numbers of basic unit circuits.

[Advantages of the Invention] As described above, the present invention is such that the terminal plate having the connecting legs is integrally assembled to the synthetic resin case by insert molding, and a rough surface is formed on the connecting leg base surface of the terminal plate. Forming a connecting hole through which resin penetrates on both side shoulders of the connecting leg base, and further forming a blocking ridge immediately inside the connecting leg base to prevent inward flow of resin from the connecting leg base. Therefore, there is an excellent effect that the connection strength between the terminal plate and the synthetic resin case and the airtightness inside the synthetic resin case can be improved.

[Brief description of drawings]

1 to 6 show an embodiment of the present invention, FIG. 1 is an exploded perspective view of an electric filter F, FIG. 2 is a cross-sectional plan view of a synthetic resin case 1 formed by insert molding, and FIG. Is a vertical side view of the same, FIG. 4 is a plan view of the ground terminal plate 9, FIG. 5A is an enlarged sectional view taken along the line AA of FIG. 4, and FIG. 5B is a sectional view of FIG.
FIG. 6 is an enlarged sectional view taken along line A, FIG. 6 is a front view of each member mounted on the synthetic resin case 1, and FIG.
9t is a perspective view seen from the bottom in a bent state, FIG. 8 is a vertical sectional side view in an attached state, and FIG. 9 is a filtering circuit diagram. DESCRIPTION OF SYMBOLS 1 ... Synthetic resin case 2 ... Opening surface 4a, 4b ... Series resonator 5a, 5b ... Parallel resonator 6,8, 9 ... Terminal plate 9a, 9a ... Shoulder part 9b ... Connection leg base 9c ... Rough surface 9d, 9d ... Connection hole 9e ... Blocking ridge 6t, 8t, 9t ... Connection leg 17 ... Sealing plate 18a, 18b ... Insertion hole

Claims (1)

[Scope of utility model registration request] 1. A terminal plate of any one of an input side terminal plate, an output side terminal plate and a ground side terminal plate provided with connecting legs is integrally assembled with a synthetic resin case by insert molding, and one of the cases is formed. Insert the series resonators, parallel resonators, and other terminal plates, etc., which are connected to each terminal plate and have the required connections, from the openings formed on the other side surface of the case, with the connecting legs protruding from the side surfaces. In a ladder-type electric filter in which connecting legs are projected from the other side surface of the case, a rough surface is formed on the base surface of the connecting legs embedded in the case of the terminal plate assembled to the synthetic resin case, A connecting hole through which resin penetrates is formed on both side shoulders of the connecting leg base embedded in, and a blocking ridge that prevents resin from flowing inward from the connecting leg base is formed just inside the connecting leg base. A ladder type electric filter characterized by the above.